Why do my Stella de Oro' lilies stop blooming?

I have multiple types of lilies in my garden. My other lilies are doing well, except my Stella de Ora. They use to bloom all summer long(June-early September). The last few years, they would bloom profusely,but then new pods form, and never open. The pods continue to turn to seed. I know I have to divide them, for they are way overdue, but what can I do to prevent the new growth from going to seed pods? At the present time they are blooming beautifully, with lots of new stems. What can I do to keep them blooming? Any help most welcome, Thanks to all.Why do my Stella de Oro' lilies stop blooming?
You've already hit on the major thing you need to do...divide them...If you don't have the room for more plants give some to your neighbors...Another trick would be to go out every day and pick off all the spent blooms(do this very gently, you don't want to loose any flower buds)...This will inhibit seed production...The third thing you can do is fertilize, use a product that says something like ';bloom booster';...When you read the numbers on the back; make sure the second number is larger than the first number(Ok a quick fertilizer 101-the first number is always nitrogen, the second phosphorus, and the third potash; phosphorus, promotes root growth, and flower production...)...Do this every 7-10 days; however stop fertilizing no later than the second week of August...Why do my Stella de Oro' lilies stop blooming?
Same thing is happening to my Stella de Oro's. I definitely need to separate them.
No answer but a grateful thumbs up. I want to thank the horticulturist (hope I said that right) for the great answer as I have the same problem. Out to the garden I go!